Safety device for elevators



Patented July 11, 1922.

2 SHEETS-SHEET I.

INVENTOI? Haeey/Va G/AL/VEQ)" A TTORNEYS H. McGlLLlVR'AY.

SAFETY DEVICE FOR ELEVATORS.

' APPLICATION FILED MAR- 22, 1921.

1,422,774, Patented July 11, 1922,

2 SHEETS-SHEET 2. "T 15". 5. m n 7" 22"",:: HIV/22 6 a. m I I 54 55 2$[2R I H I mu, NHL 20-h .;m mm. mm

WITNESSES IN VE N TOR ATTORNEYS UNITED STATES,

PATENT OFFICE.

SAFETY nnvrcn FOR ELEVATORS.

Application filed. March 22, 1921.

the cables by which the same are supported- Another object in view is toprovide in connection with a means for automatically stopping andlocking an elevator in event of the breaking of the cable, a means forsimultaneously cutting off power for driving the same.

A still further object in view resides in the provision of a safetydevice for elevators which includes pivoted levers having cammedextremities normally retained out of engagement with the guide rails ofthe shaft by supporting cables for the elevator which cables areconnected with the pivoted levers. I

A further object of the invention resides in the provision of a safetydevice includ ing pivoted levers, the cammed extremities of which areprovided with guide flanges which function to maintain said extremitiesin juxtaposition at all times.

A still further object in view resides in the provision of a safetydevice including pivoted levers with cammed extremities which areadapted to be thrown to active position by means of springs in whichmeans is provided for relieving the springs of wear when the levers arenormally retained in in active position.

Another object is the provision of a safety device of the characterdescribed which is simple in cgnstruction,inexpensive to manufacture andinstall and which is thoroughly reliable and highly efficient in itspurpose.

With the above recited and other objects in view, the invention residesin the novel construction, combination and arrangement of parts setforth in the following specification, pointed out in the appended claimsand illustrated in the accompanying drawings, in which;

Specificationof Letters Patent.

PatentedJuly 11, 1922.

Serial No. 454,330.

Figure 1 is a fragmentary front eleva tlon of an elevator and acounterweight therefor equipped with a safety device con.

, tuting a part of the invention.

Figure 3 is a fragmentary enlarged front elevation of the upper portionof the car, parts being "broken away to disclose the underlyingstructure and illustrating in. dotted and full lines normal and actuatedposition of the parts. f

Figure 4 is a horizontal plan view taken approximately on the line l 1of Figure 3.

Figure 5 is a vertical transverse sectional view taken approximately 011the line 5-5 of Figure 3.

Figure 6is a similar sectional view taken approximately on the line 66of Figure 3.

Figure 7 is an enlarged fragmentary elevation of the counterweightattachment, parts being shown in section. v

Figure 8 is a horizontal sectional view therethrough taken approximatelyon the line 8-8 of Figure 7.

Referring to the drawings by characters of reference, 10 designates anelevator shaft provided with vertical T-shapecl guide rails 11-11disposed centrally at the opposite sides thereof over which the car 12is guided. The car is provided with the usual super structure whichincludes the transverse channel iron beams 13-13. The shaft and car maybe of any approved type now in general use, the showing made in thedrawing being merely illustrative of one form to which the safetyattachment may be applied. The safety 7 attachment comprises a pair oflevers 1414 each of which is pivoted adjacent its "outer end as at 15underneath the outer ends of the beams 13. The outer extremities of thelevers 14 are enlarged as at 1 6 and said enlarged extremities areprovided with cammed outer end walls 17 I which are designed to bedisposed out of contact with the rails 11 when the inner extremities ofthe levers 14 are swung upwardly. The inner extremities of the leversare apertured as at 18 for the reception of the vertical bolts 19 Theupper endsof the bolts 19 are provided with bifurcated heads '20 injwhich a're received the looped terminals 21 of the su portin cables 22.The cables 22 are trained 7 over t, e "guide pulleys 23 arranged at thistop of the shaft and the opposite loop terminals 24 of said cables areconnected to the counterweight 25 in a manner to be hereinafter setforth. A plate 26 is bolted or otherwise secured to the under side ofthe channel beams 13 to straddle the same and said plate is providedwith spaced apertures 27 through which the bolts 19 extend. A hearingsleeve 28 is arranged over each bolt 19 and is disposed between theinner end of the lever and the under side of the plates 26. The lowerend of each bolt 19 has mounted thereon a ball race 29 in which theantifriction balls 30 and retained. A pair of lock nuts 31 are threadedon the lower end of the bolt to retain the ball race 29 thereon. Awasher 32 is secured to the under side of the inner end of each lever 14with its central aperture in alignment with the aperture 18. A coiledcontractile spring 33 surrounds each sleeve 28 and bolt 19, the oppositeends thereof respectively bearing on the plate 26 and the upper side ofthe inner end of the levers 14. The counter weight 25 is provided with apair of levers 34 each of which are pivoted as at extremities 35adjacent their enlarged outer extremities 36 to the under side of thetransverse beam 37 of the superstructure. The outer end of the levers 34are cammed as at 38 and are adapted to normally be disposed out ofengagement with the guide rails 39 for the counter weight when the innerextremities of the levers 34 are swung upwardly. The locked terminals 24of the supporting cables 22 are connected to the inner arms of thelevers 34 by the bolts 40. A coiled contractile spring 41 is interposedbetween a plate 42 secured to the beam 37 and a plate 43 secured to theupper side ot the extreme inner end of the levers 34. A suitable spacingsleeve 44 is carried by the plate 42 and is arranged within theconvolutions of the springs 41 for the purpose of supporting the innerend of the lever 34 prior to the complete compression of the springs 42.The outer enlarged extremities of the levers l4 and 34 are each providedwith flanges 45 which extend outwardly from. the ends and embrace theguide rails 11 and 39 respectively for maintaining the cammed outer endwalls in juxtaposition thereto.

The circuit wire 50 which leads from the source of supply to thecontroller handle 51 is arranged to traverse the beam 13. The circuitwire 50 is broken at two points 52 and 53 and is provided with spacedterminals 54 and 55 adjacent each of said gaps. A bridge element 56 isprovided for each gap or brake 52 and 53. The bridge elements 56 arerespectively mounted on a vertically movable rod 58 mounted in suitableguides on the beam 13. The lower extremity of each rod 58 is providedwith a roller 59 which co-acts with the upper surface of the lever 14.By this arrangement when the levers 14 are swung upwardly to normalposition, the bridge element 56 will bridge the gaps and establishcommunication between the contact terminals 54 and 55.

In operation of the device the supporting cables 22 normally support theweight of the car 12 and the counter weight 25 through the bolts 19 and40 respectively. The upward pull on said bolts will ellect contact ofthe sleeves 28 with the plates 26, the contact of the ball race with thewasher and the contact of the inner end of the levers 14 with thesleeves thereby compressing the springs 33. At the same time the innerend of the levers 34 ot the counter weight will be hcl d in contact withthe spacer sleeves 44. The length of the sleeves 28 and beingsillficient to prevent the entire compression ol? the springs 33 and 41.The anti-it'rictiou balls 30 will permit the bolts 19 to rotate wherebyto relieve the cable of any kinks or twist which may occur therein.

In this position the outer cammed extremities or walls 17 and 38 of thelevers 14 and 34 will be maintained out of contact with the guide rails11 and 39. In event of the breaking of all of the supporting cables 22,the springs 33 and 41. will be instantly released to effect a downwardmovement of the inner ends of the levers 14, and 34 respectively therods 58 will gravitate to break the circuit wire 50 by opening the gaps52 and upon movement of the bridge elements 56 out or contact with theterminal contacts 54 and This will automatically cut oii? the power. Tnevent of the breaking of one of the cables only, the downward movementof one of the levers 14 will break the circuit wire 50 to cut of? thepower without jamming the car so that repairs can be made before theother cable is severed.

lVhile there has been illustrated and described a preferred embodimentof the invention. no limitation is necessarily made to the precisestructural details therein exhibited as it is to be understood thatvariations and modifications that properly fall within the scope of. theappended claims may be resorted to when found expedient.

I claim:

l. The combination with an elevator shaft having vertical guide rails, acar a plurality of supportingcables therefor, independent means carriedby the car and attached to each supporting cable adapted to coact withthe guide rails for i rictionally locking the car within the shaft uponbreaking of the supporting cables and a circuit adapted when closed tooperate the car, of circuit breakers normally held in circuit closingrelation by the levers for completing the circuit and operable bymovement of said levers upon breaking of any of the cables to open thecircuit for stopping the car.

2. In a safety device for elevators, the combination with an elevatorcar and counterweight therefor movable between vertical guide rails, ofmeans for frictionally locking the car and the counterweight withln theshaft comprising a pair of levers carried respectively by the car andthe counterweight, each of said levers including a cammed head, meansfor rocking the levers to effect frictional engagement of the same withthe guide rails, and a pair of cables constituting a connection betweeneach car lever and counterweight lever for holding the levers normallyin an inactive position to retain the cams out of engagement with theguide rails, in combination with a circuit serving when closed tooperate the car and including an operating controller switch, a pair ofcircuit breakers, each normally held in circuit closing relation by oneof the car levers and operable upon breaking of the cables to open thecircuit for stopping the car.

8. In a safety device for elevators, the combination with an elevatorcar and counterweights therefor movable between vertical guide rails inthe elevator shaft, of means for frictionally locking the car andcounterweights within the shaft in event of breaking of the cables,comprising levers pivoted respectively to the car and counter weight,each of said levers including cammed heads, a spring adapted to coacttherewith for rocking the lever to a position to effect frictionalengagement of the cammed head with the guide rail, a cable connectionbetween each set of car and counterweight levers for holding the leversnormally inactive to retain the cammed heads out of engagement with theguide rails, and means interposed between the lever and the car oreounterweight structure constituting the abutments for limiting thecompression of the springs whereby the carrying load is carried by saidmeans.

at. In a safety device for elevators, the combination with an elevatorcar and counterweights therefor movable between vertical guide rails inthe elevator shaft, of means for frictionally locking the car andcounterweights within the shaft upon breaking of the cables, comprisinga plurality of levers pivoted respectively to the car andcounterweights, a cammed head on each of said levers having side flangesprojecting outwardly therefrom to retain the same in juxtaposition tothe guide rail, a spring adapted to coact therewith for rocking thelever to effect frictional engagement of the same with the guide'rail,cables respectively attached at their opposite ends to one of the leversof the car and one of the levers of the counterweight for connectiongthe same and for holding the levers normally inactive to retain thecammed heads out of engagement with the guide rails, and means coactingwith each lever of the car for throwing off the power to bring the carto a stop in event of breaking of its cable.

5. In a safety device for elevators, the combination with an elevatorcar and counterweights therefor movable between vertical guide rails inthe elevator shaft, of means for frictionally locking the car andcounterweights within the shaft upon breaking of the cables, comprisinga plurality of levers pivoted respectively to the car andcounterweights, a cammed head on each of said levers having side flangesprojecting outwardly therefrom to retain the same in juxtaposition tothe guide rail, a spring adapted to coact therewith for rocking thelever to effect frictional engagement of the same with the guide rail,cables respectively attached at their opposite ends to one of the leversof the car and one of the levers of the counterweight for connecting thesame and for holding the levers normally inactive to retain the cammedheads out of engagement with the guide rails, and means coacting witheach lever of the car for throwing off the power to bring the car to astop in event of breaking of its cable, said means comprising in theoperating circuit of the car a plurality of gaps corresponding to thenumber of levers,

a movable rod having a bridge member carried thereby, said rod havingengagement with the lever for normally holding the bridge member carriedthereby, said rod having engagement with the lever for normally holdingthe bridge member in bridging relation to the gap when the lever is 1nnormal position.

HARRY MGGILLIVRAY.

